/* 全局样式 */
.hero-bg {
    background: linear-gradient(135deg, #1a365d 0%, #2d3748 100%);
}

/* 功能卡片样式 */
.feature-card {
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 1rem;
}

/* 语言选择器样式 */
.language-selector {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 60;
}

.language-selector select {
    padding: 0.5rem;
    border-radius: 0.375rem;
    border: 1px solid #e2e8f0;
    background-color: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.language-selector select:hover {
    border-color: #3b82f6;
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.1);
}

/* 语言切换过渡效果 */
.lang-transition {
    transition: all 0.3s ease;
}

.lang-transition.fade-out {
    opacity: 0;
    transform: translateY(10px);
}

.lang-transition.fade-in {
    opacity: 1;
    transform: translateY(0);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero-bg {
        background: linear-gradient(135deg, #1a365d 0%, #2d3748 100%);
    }
    
    .feature-card {
        margin-bottom: 1rem;
    }

    .language-selector {
        top: 0.5rem;
        right: 0.5rem;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fade-in {
    animation: fadeIn 0.5s ease-out forwards;
}

/* 加载动画 */
.loading {
    position: relative;
    overflow: hidden;
}

.loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0% {
        transform: translateX(-100%);
    }
    100% {
        transform: translateX(100%);
    }
}

/* 错误提示样式 */
.error-message {
    position: fixed;
    top: 1rem;
    left: 50%;
    transform: translateX(-50%);
    background-color: #ef4444;
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 0.375rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    z-index: 100;
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from {
        transform: translate(-50%, -100%);
    }
    to {
        transform: translate(-50%, 0);
    }
}

/* 导航链接动画 */
.nav-link {
    position: relative;
    transition: all 0.3s ease;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 50%;
    background-color: #2563eb;
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.nav-link:hover::after {
    width: 100%;
}

/* 导航栏滚动动画 */
.nav-scrolled {
    backdrop-filter: blur(8px);
    background-color: rgba(255, 255, 255, 0.95);
    transform: translateY(0);
    transition: all 0.3s ease;
}